Water pump leak?

ESGWheel

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Oh boy, not good….

With plugs all out and block drained down crank it over to clear any water out of #4 and redo test on 4
 
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Jul 3, 2025
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Oh boy, not good….

With plugs all out and block drained down crank it over to clear any water out of #4 and redo test on 4
Will do. Only thing that may also be worth mentioning is couldn’t get the motor to turn with the starter when we only took 1 plug out and left the rest in. Had to take them all out and then could use the starter to turn over for the testing. Not sure how that affects the results or what could cause that. Battery shouldn’t have been low. Never done a compression test before but I thought you could do them 1 at a time.
 
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Jeff J

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The motor was probably hydro locked on #4. Water does not compress so the starter could not crank it. You would be looking at serious damage if it had.

It’s best to do a compression test with all plugs removed. The starter spins the motor better that way.
 

ESGWheel

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The reason it would not turn over is because of “hydrolock”. Google it for more info but it comes down to water is not compressible > you had that cylinder filled with water and as it came up on its compression stroke, the water cannot compress and thus it stopped turning. Given this was done by the starter, it probably did not break anything. Note: its possible to get water ingested thru the exhaust system in a sterndrive if you come off plane too rapidly and since the engine is running when the hydrolock happens, things break.

That said I am a little confused as to the possible source of the water > you had previously run the engine as stated in your initial post, so clearly was not hydrolocked. But you said you got some water into the head when removing the risers and manifolds. As Click and Clack would say if you have led a good clean life, the spillage is the source, and you do not have a cracked head and/or block nor a bad head gasket. This is the reason to retest No. 4 post getting all the water out by cranking it.

If it shows bad compression, then it would be time for a leak down test to determine why. And from that can make determination of pulling motor or just pulling heads (with motor still in boat).
 
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The reason it would not turn over is because of “hydrolock”. Google it for more info but it comes down to water is not compressible > you had that cylinder filled with water and as it came up on its compression stroke, the water cannot compress and thus it stopped turning. Given this was done by the starter, it probably did not break anything. Note: its possible to get water ingested thru the exhaust system in a sterndrive if you come off plane too rapidly and since the engine is running when the hydrolock happens, things break.

That said I am a little confused as to the possible source of the water > you had previously run the engine as stated in your initial post, so clearly was not hydrolocked. But you said you got some water into the head when removing the risers and manifolds. As Click and Clack would say if you have led a good clean life, the spillage is the source, and you do not have a cracked head and/or block nor a bad head gasket. This is the reason to retest No. 4 post getting all the water out by cranking it.

If it shows bad compression, then it would be time for a leak down test to determine why. And from that can make determination of pulling motor or just pulling heads (with motor still in boat).
Couple things, short version 1st. Standing water is still in intake manifold area with water pump, manifolds and all drain plugs removed (pics attached). I assume this means there is a clog(s) somewhere between the intake and the circulation pump.
After draining the water from the block drains, and trying to push the water out of cylinder 4, the compression tested at 200. However, water was still misting out of the exhaust port for #4 while doing the test. Thats why we started removing the water pump and intake manifold drain plugs removed to make sure all the water was out before resuming the test. We obviously couldn’t get all the water out because even with all the plugs and the water pump removed, there is still water in the intake manifold area. Pictures below are of the visible water in the intake manifold area, and dry circulation pump ports.
I’m still not sure if the water that shoots out of the exhaust port while running the compression test is residual water that was in there, or if it’s pulling more water in as we crank it.

Also found a jasper tag on it, called them and the motor was sold in 2020

And a moment to say thank you to @ESGWheel and everyone else for helping me on this. Absolutely would not have made it this far without your help.
 

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ESGWheel

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So much for the good clean life. At least you and your neighbor are going to have a fun project this winter.

My suggestions are:
Pull off the heads now and see how extensive the damage is. Perhaps damage just in the top end (not the block / pistons). The risk here is running out of time and if need to pull motor may not have the time before needing to set up for the Kansas City winter. Also risk that you do not see any issues with the bottom end but in fact it does have issues. Thus, do heads only to discover later (after all together) that need to do the block. This is the benefit of being able to do the leak down test > are the piston rings OK?

As a type this, I now think most logical thing to do is get that water out and do a leak down test. Your block drains may be plugged, so use a coat hanger or something and jam it in there. But given it’s a 2020 rebuilt motor I suspect they are OK. A little residue water I the intake manifold is ok but might as well just take it off along with the exhaust manifolds > this way no water but can still do the compression / leak down testing.

Keep everything neat and organized and labeled when you start pulling apart. Read thru this recent thread for some tips on that Link.

With the leak down test completed, you will know if the rings need attention > hopefully not. And thus, can just pull heads and be comfortable when all back together you have a great running boat.
 

dypcdiver

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And don't forget that the reason for the spray of water is a compromised rear seal in the raw water pump. A rebuild is a doddle, new bearing and seal is about $50.
 

Donald0039

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And don't forget that the reason for the spray of water is a compromised rear seal in the raw water pump. A rebuild is a doddle, new bearing and seal is about $50.
I bought both the seal and bearing. The I could not detect any issues with the bearing so I only replaced the seal. Replacing the bearing is a lot more work as it's pressed in.
 

dypcdiver

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OK, the choice is yours, but think about how does the water escape other than passing by the bearing.
 
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So much for the good clean life. At least you and your neighbor are going to have a fun project this winter.

My suggestions are:
Pull off the heads now and see how extensive the damage is. Perhaps damage just in the top end (not the block / pistons). The risk here is running out of time and if need to pull motor may not have the time before needing to set up for the Kansas City winter. Also risk that you do not see any issues with the bottom end but in fact it does have issues. Thus, do heads only to discover later (after all together) that need to do the block. This is the benefit of being able to do the leak down test > are the piston rings OK?

As a type this, I now think most logical thing to do is get that water out and do a leak down test. Your block drains may be plugged, so use a coat hanger or something and jam it in there. But given it’s a 2020 rebuilt motor I suspect they are OK. A little residue water I the intake manifold is ok but might as well just take it off along with the exhaust manifolds > this way no water but can still do the compression / leak down testing.

Keep everything neat and organized and labeled when you start pulling apart. Read thru this recent thread for some tips on that Link.

With the leak down test completed, you will know if the rings need attention > hopefully not. And thus, can just pull heads and be comfortable when all back together you have a great running boat.
So pulled the intake off, and don’t see any clogs. I was expecting to see something….
I didint realize the rear holes were closed off. So I think the water that was in the intake manifold was just from the boat being tilted slightly back.
 

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It’s pretty rusty in there. I think I need to check and clear the water jacket for blockages. Does anyone know how I would go about doing this? I haven’t had any luck finding a good how-to online. Also wondering if maybe it’s time to start a new post as this has drifted far away from a “water pump leak”.
 

Bondo

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It’s pretty rusty in there. I think I need to check and clear the water jacket for blockages. Does anyone know how I would go about doing this? I haven’t had any luck finding a good how-to online. Also wondering if maybe it’s time to start a new post as this has drifted far away from a “water pump leak”.
Ayuh,...... No real need for a new thread,... In yer pictures above, it ain't all that rusty to cause yer issue, I've seen much, Much worse,.....
Short of pulling the motor, to remove the core plugs, I suggest you put the intake back on, with new gaskets, then you can flush the block, with the block drains removed, 'n prod the holes with a big screw, or nail to remove any crud that shows up,.....
The odds of the block being plugged up are slim, to none,.... After all, it's only 5 years old,.....
If the intake manifold is responsible for the water getting into the cylinders, it's most likely it rusted through under the t-stat, which isn't shown in yer pictures,... That's where intake manifolds fail,....
What I don't see mentioned, is whether this motor was replaced using the original intake, 'n exhaust manifolds,....
 

ESGWheel

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Waterman, sorry for delay in getting back to you. Were you able to run the compression test / leak down prior after pulling the manifolds and clearing the water out of the cylinders (crank engine over without plugs)? Recall this will be the telltale of how far one must go or at least provide an indication of it.

Agree the rust you are seeing in the manifold it typical and not an issue. In fact, a light coating of rust is in of itself an inhibitor of more rust. Think of this way > say you get the passages shinny clean, you just exposed fresh metal to rust, and it will do so quickly. But once rusted slows down further rusting.

Back on topic: you are currently faced with the following:
  1. Determining where the water in the cylinders was coming from (see Bondo’s post # 52)
  2. Determining extend of damage, if any, due to the water in the cylinder (like damaged rings, hence leak down test)
  3. And based on above, either pulling heads or pulling motor.
Keep posting and asking questions, we need to get u back on the water for next season!
 
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Ayuh,...... No real need for a new thread,... In yer pictures above, it ain't all that rusty to cause yer issue, I've seen much, Much worse,.....
Short of pulling the motor, to remove the core plugs, I suggest you put the intake back on, with new gaskets, then you can flush the block, with the block drains removed, 'n prod the holes with a big screw, or nail to remove any crud that shows up,.....
The odds of the block being plugged up are slim, to none,.... After all, it's only 5 years old,.....
If the intake manifold is responsible for the water getting into the cylinders, it's most likely it rusted through under the t-stat, which isn't shown in yer pictures,... That's where intake manifolds fail,....
What I don't see mentioned, is whether this motor was replaced using the original intake, 'n exhaust manifolds,....
I don’t know if the manifolds are original or not. I would assume they predate the motor. The intake gasket is an automotive gasket so I assume the motor from jagers may not have been assembled for marine use. The intake doesn’t appear to be rusted out. I’m wondering if I should test the exhaust manifolds and risers for leaks but I’m not sure the best way to do it.

I’ll retest compression on #3 (I had them backwards before) when it’s not raining. When I tested it before with most of the water out it was at 200.

Also as I type this, maybe it makes sense to pull the heads just so I can make sure a marine gasket is in there. My understanding is you can get away with auto gaskets for some things if used in freshwater (although shouldn’t), but not the head gasket. Then I can also see if the gasket is damaged and was letting water in. The felpro automotive intake gasket that we took out still looked practically new so I don’t know.
 

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ESGWheel

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Waterman,
Pulling the heads will only get you so far unless there is obvious visual damage in the block. I cannot stress enough that water in cylinders can do great harm > easily destroy a motor with one stoke of a cylinder. Since you have that handy neighbor, I continue to recommend get ALL the water out of the cylinders by having all plugs removed and crank until no water. If there is spray out of the cylinders, keep going. Best to disable the ign system for this.

Now redo the compression test and then go to the leak down test as suggested in post no. 53.

Here is the risk if you do not follow this: you pull the heads, find a bad head gasket, get it all replaced and back together again only to find you have cracked rings in that no. 3 cylinder, so now pulling the engine out and doing it all over… another season down for the count.

While I am hopeful no block issues, given you have the oppy to find out, why not do so?
 
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